Conventionally, upon planning of a vehicle, two-dimensional (2D) drawings that represent an outline of that vehicle are prepared, and the feasibility of the plan is determined based on the drawings. When there are changes in the plan, drawings are prepared from the beginning.
Therefore, in the conventional planning process, much labor is spent for preparing the drawings, thus requiring much time and cost. Furthermore, it is difficult to grasp an image of the vehicle on the 2D drawings.
Conventionally, in the drawing preparation process, an acceptable exterior shape which should have a large degree of freedom tends to be adopted while being restricted by factors with a small degree of freedom such as an interior for passengers and the like, and it is harder to produce a vehicle with a daring design.